The present invention relates to electrical measurements and, in particular, to impedance meters.
Referring to FIG. 1, an impedance meter 10 is used to measure a test impedance 12. Typically, the meter 10 will have multiple measurement ranges. The multiple ranges help ensure that a measurement can be performed in a range for which the circuit parameters have been optimized for impedances in that range. It is common for the ranges to partially overlap. Measuring an impedance usually includes a current measurement. This is typically done by measuring the voltage drop across a current-sensing resistor in the meter.
A basic requirement for measurements is that a meter be calibrated so the measurements actually correspond to the desired units of measure. It is important to not only initially calibrate a meter, but also, to keep it calibrated.